IIT JEE Practice Question and Answer
8Q: Two parallel chords on the same side of the centre of a circle are 5 cm apart. If the chords are 20 and 28 cm long, what is the radius of the circle? 1008 05b5cc73ae4d2b4197774f8f7
5b5cc73ae4d2b4197774f8f7- 114.69 cmfalse
- 215.69 cmtrue
- 318.65 cmfalse
- 416.42 cmfalse
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Answer : 2. "15.69 cm"
Explanation :
Answer: B) 15.69 cm Explanation: Draw the two chords as shown in the figure. Let O be the center of the circle. Draw OC perpendicular to both chords. That divides the two chords in half.So CD = 10 and AB = 14. Draw radii OA and OD, both equal to radius r.We are given that BC = 5, the distance between the two chords. LetOB = x. We use the Pythagorean theorem on right triangle ABO AO² = AB² + OB² r² = 14² + x² We use the Pythagorean theorem on right triangle DCO DO² = CD² + OC² We see that OC = OB+BC = x+5, so r² = 10² + (x+5)² So we have a system of two equations: r² = 14² + x² r² = 10² + (x+5)² Since both left sides equal r², set the right sidesequal to each other. 14² + x² = 10² + (x+5)² 196 + x² = 100 + x² + 10x + 25 196 = 125 + 10x 71 = 10x 7.1 = x r² = 14² + x² r² = 196 + (7.1)² r² = 196 + 50.41 r² = 246.41 r = √246.41 r = 15.69745202 cm
Q: Intermolecular forces in HCl are 1008 05b5cc658e4d2b4197774bd9e
5b5cc658e4d2b4197774bd9e- 1Hydrogen bondingfalse
- 2Dipole-dipolefalse
- 3Dispersion forcefalse
- 4All the abovetrue
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Answer : 4. "All the above"
Explanation :
Answer: D) All the above Explanation: Intermolecular forces : The forces of attraction present in between the molecules or atoms or compounds is termed as intermolecular forces. The molecule HCl is composed of hydrogen and chlorine atom. There is high difference in electronegativities therefore, it is polar in nature. The H end of HCl is permanently slightly positive charge. The Cl end of HCl has a permanent slight negative charge. the "H" in one molecule is attracted to the "Cl" in a neighbor. The intermolecular force is weak compared to a covalent bond. But this dipole-dipole interaction is one of the stronger intermolecular attractions. It also has hydrogen bonding and dispersion forces. Dispersion forces are the weakest forces which are present in between all molecules or atoms.Hydrogen bonds are present in molecules having at least one H-A bond where A is the strong electronegative atom (mainly F, Cl and N).
Q: If x and y are the two digits of the number 653xy such that this number is divisible by 80, then x+y is equal to ? 1007 05b5cc761e4d2b4197774fd62
5b5cc761e4d2b4197774fd62- 15false
- 24false
- 33false
- 42true
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Answer : 4. "2"
Explanation :
Answer: D) 2 Explanation: Since 653xy is divisible by 5 as well as 2, so y = 0.Now, 653x0 must be divisible by 8.So, 3x0 must be divisible by 8. This happens when x = 2x + y = (2 + 0) = 2.
Q: The wavelength of a wave is the distance between 1007 05b5cc6b0e4d2b4197774d283
5b5cc6b0e4d2b4197774d283- 1Crest and Troughfalse
- 2Crest and Crestfalse
- 3Trough and Troughfalse
- 4Both B & Ctrue
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Answer : 4. "Both B & C"
Explanation :
Answer: D) Both B & C Explanation: Distance between two Consecutive Crests or two Consecutive Troughs is called Wavelength. But the distance between crest and adjacent trough is half the wavelength. That is the distance between adjacent crest and trough is called Half the wavelength.
Q: The Sivasamudram Falls is on which river ? 1007 05b5cc6c1e4d2b4197774db55
5b5cc6c1e4d2b4197774db55- 1Gangafalse
- 2Saryufalse
- 3Cauverytrue
- 4Krishnafalse
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Answer : 3. "Cauvery"
Explanation :
Answer: C) Cauvery Explanation:
Q: Several Budget proposals, including the reintroduction of the tax on long-term capital gains (LTCG) exceeding __ from the sale of shares, will kick in from 01st April 2018, the beginning of the 2018-19 financial year. 1006 05b5cc69ce4d2b4197774c882
5b5cc69ce4d2b4197774c882- 11 lakhtrue
- 22 lakhsfalse
- 33 lakhsfalse
- 44 lakhsfalse
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Answer : 1. "1 lakh"
Explanation :
Answer: A) 1 lakh Explanation: Several Budget proposals, including the reintroduction of the tax on long-term capital gains (LTCG) exceeding 1 lakh from the sale of shares, will kick in from 01st April 2018, the beginning of the 2018-19 financial year.
Q: Which is an example of Phototropism? 1006 05b5cc6abe4d2b4197774cfd6
5b5cc6abe4d2b4197774cfd6- 1roots of a plant following waterfalse
- 2plant bending toward the lighttrue
- 3roots growing into the soilfalse
- 4a venus flytrap capturing a flyfalse
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Answer : 2. "plant bending toward the light"
Explanation :
Answer: B) plant bending toward the light Explanation: Phototropism is the ability of a photosynthesizing organism, to grow directionally in response to a light source. It is very common in plants, but can also occur in other organisms such as fungi. Example :: Sunflower
Q: Train K crosses a stationary Train L in 50 seconds and a pole in 20 seconds with the same speed. The length of the Train K is 240 meters. What is the length of stationary Train L ? 1006 05b5cc72ce4d2b4197774f75f
5b5cc72ce4d2b4197774f75f- 160 mtsfalse
- 2120 mtsfalse
- 3240 mtsfalse
- 4360 mtstrue
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Answer : 4. "360 mts"
Explanation :
Answer: D) 360 mts Explanation: Speed of the Train K is given by s = d/t = 240/20 = 12 m/sDistance covered by Train K in 50 seconds = 12 x 50 = 600 mts.But it crosses Train L in 50 seconds Therefore, the length of the Train L is = 600 - 240 = 360 mts.